Spark-plug



G. L.'HERZ.

SPARK PLUG. APPLICATION FILED NOV- 2,1917.

1,361,580. I I Patented Dec. 7,1920.

fifty. z.

UNITED STATES GUSTAVE L. HERZ, OF NEW YORK. N. Y.

SPARK-PLUG,

Specification of Letters Patent.

Patented Dec. 7, 1920.

Application filed November 2, 1917. Serial No. 199,848.

To all whom it may concern:

Beit known that I, GUSTAVE L. Hunz, a citizen of the United States, and resident of the borough of Manhattan, in the city and State of New York', have invented a new and useful Improvement in Spark- Plugs, of which the following is a specification.

The object novel means to prevent the short-circuiting of a spark plug-by oiling or sooting up, said means including an oil and soot guard, as for instance a metal disk, located at a distance inwardly from the sparking points of the electrodes and between the sparking points and insulator.

'- My invention more specifically includes of the electrodes so as tion applied thereto.

-' insulator by 2,

a cup-shaped disk located within the spark plug shell and having a concave-convex bottom surrounding the' center electrode. The space betweenthe inner edge of the guard and the center electrode'should be greater than the space between the sparking points to preclude the possibility of the spark forming between the center electrode and the guard.

Practical embodiments of. my invention are represented in the accompanying drawinqs in which,

*ignre 1 represents a spark plug of one type, partly in side elevation and partly in with my invenlongitudinal central section,

-Fig..2 is an end view of the plug, and

Fig. 3 is a cross sectiontaken in the plane of the line III-III of Fig. 1.

, Fig; 4 is a detail longitudinalcentral section of another form of plug with my 1nvention applied thereto, and Fig. 5 is a detail longitudinal section tion.

In the form shown in Figs. 1, 2 and 3, the spark plug shown isdenotedby 1, the the center electrode by 3 and the disk shell electrode by 4. These partg'may be-of well known or approved form.

In the forms shown in Figs. 1 to 4 inclusive, the oil and soot guard is located within the shell at a distance inwardly from the s arking points of the electrodes, and is sliown as comprising a cup-shapeddlsk 5 having a concave-convex bottom 6 directed toward the sparking points and surrounding the center electrode 3 and spaced thereof my invention is to provide from a greater'distance than the spark gap at the sparking points of the electrodes.

The inner edge of the guard is preferably beaded as shown at 7, to still further prevent anyliability of the spark gap forming at this point. The outer edge of the guard is shown as united to the outer edge of the shell disk electrode 4, and the so united outer edges are shown as secured to the shell by crimping over the end 8 thereof.

In the form shown in Fig. 4, a bent rod 9 forms the shell electrode instead of the disk. 4 as shown in the other figures. In this form the outer edge of the oil and soot guard 1s secured to the end "of the shell by crimping the same over the outer edge of the guard. I

In the-form shown in Fig. 5, the oil and soot guard' is of a slightly different form and is located exterior to the shell but still Q at a distance inwardly from thesparking Y points and between the sparking points and insulator; i

The location of this oil and soot guard at a distance inwardly from the sparking points of the electrodes and between the sparking points and insulator, serves to prevent the deposit of the oil and soot along the walls of the shell and the walls of the insulator, thus preventing the short circuiting of the plug from this cause and prolonging the effective life of the plug.

It is obviousthat the forms of guard which I have chosen to illustrate are only two of many forms which it might assume, without departing from the spirit and scope of my invention, and hence I do not wish to limit myself to the particular forms herein shown, but- What I claim is:

1. In aspark plug, a cup-shaped metal disk located within the spark plug shell between the inner end of the insulator and the sparking points of the electrodes, said disk having a concavo-convex bottom surrounding the center electrode, the inner edge of the disk being beaded and spaced a greater distance from the center electrode than the distance between the sparking points.

2. In a spark plug, a cup-shaped metal disk located within the spark plug shell between the inner end of the insulat r and the sparking points of the electrod said disk surrounding, the center electrode, the inner edge ofthe disk being spaced a greater shell electrode comprising a metal disk cated at the inner end of the shell.

3. In a spark plug, a cup-shaped metal disk located within thespark plug shell betweenthe inner end of the insulator and the sparking points of the electrodes, said disk surrounding the center electrode, the

inner edge of the disk being spaced at greater distance from the center electrode than the shell electrode comprising a metal disk 10- cated at the inner end of the shell, the'outer edge of the cup-shaped metal disk being permanentlyunited to the outer edge of the shell disk electrode.

4. In a spark plug, a cup-shaped metal disk located within the fspark pluglshell bedistance from. the center electrode than the distance between the sparking points, the shell electrode comprising a metaldi'sk located at the innerendof the shell,-the outer edge of the cup-shaped metal disk being v permanently united'to the outer edge ofthe distance. between the sparking points the shell disk electrode, and'the outer edgqof the shell being crimpedvover the so united edges to secure the two disks to the shell. Intestimony, that I claim theforegoing as my invention, I have signedmy name this 26thday of October, 1917.

GUSTAVE L. HERZ- 

